1. Field of the Invention
The present invention relates to the field of display technology, and in particular to a liquid crystal display panel.
2. The Related Arts
Liquid crystal displays (LCDs) have a variety of advantages, such as thin device body, low power consumption, and being free of radiation, and are thus used widely, such as liquid crystal televisions, mobile phones, personal digital assistants (PDAs), digital cameras, computer screens, or notebook computer screens, and take a leading position in the field of tablet computers.
A liquid crystal display panel is generally composed of a color filter (CF) substrate, a thin-film transistor (TFT) array substrate, and a liquid crystal interposed between the CF substrate and the TFT substrate. The operation principle of the liquid crystal display panel is that a driving voltage is applied to two glass substrates to control the rotation of the liquid crystal molecules contained in the liquid crystal layer in order to refract out light from the backlight module for displaying an image.
With the development of the liquid crystal display technology, the resolution of the liquid crystal panel is increasingly improved and the size of sub-pixels is getting smaller and smaller. As shown in FIGS. 1a, 1b, and 1c, which respectively illustrate curves of color shifting of red (R), green (G), and blue (B) sub-pixels with respect to variation of view angle, it is clear from comparison of the three drawings that in a large view angle, the color shifting of the red sub-pixel is worst, that of the blue sub-pixel is less, and that of the green sub-pixel is the least.
FIG. 2a illustrates transmission spectra of red, green, and blue light, wherein Y1, Y2, and Y3 respectively represent transmission rates of red, green, and blue light with respect to the variation of wavelength, and Y4 represents a curve indicating human eyes perceiving stimulation of brightness. It is obvious that the transmission wave band of green light mostly coincides with the perception curve of brightness stimulation. In other words, human eyes are most sensitive to the green light wave band. FIG. 2b lists measurements of transmission of red, green, and blue light through a normal photoresist film thickness of 2.1 μm, where the transmission of green light is the highest and is 52.17%; that of red light is the next highest and is 18.24%; and that of blue light is the lowest and is 8.88%.
When an observer observes an image displayed on a display device, as shown in FIG. 3, if the observation is made inclined at the left-hand side, then a fraction of light travels inclinedly from the array substrate side of the green sub-pixel zone G and passes through the blue sub-pixel zone B to get incident onto human eyes, so that the observer would see a green image partly mixed with blue light and large view angle color shifting results. For the same reason, for inclined view of observation from the left-hand side, it is possible that the observer would see a red image mixed with green color, a green image mixed with blue color, and a blue image mixed with red color; and for inclined view of observation from the right-hand side, it is possible that the observer would see a red image mixed with blue color, a green image mixed with red color, and a blue image mixed with green color. This, when taken into consideration together with the analysis provided with FIG. 2a, indicates in large view angle color shifting, the extent of color shifting would be severest for rod images, that of the blue images is less severe, and that of the green images is the least severe.